From: Rob Herring <robh@kernel.org>

Date: Wed, 8 Dec 2021 14:11:20 -0600

Subject: x86: perf: Move RDPMC event flag to a common definition

Git-commit: 369461ce8fb6c8156206c7110d7da48e9fbc41bb

Patch-mainline: v5.17-rc1

References: jsc#PED-1754 (dependent patch)

In preparation to enable user counter access on arm64 and to move some

of the user access handling to perf core, create a common event flag for

user counter access and convert x86 to use it.

Since the architecture specific flags start at the LSB, starting at the

MSB for common flags.

Cc: Peter Zijlstra <peterz@infradead.org>

Cc: Ingo Molnar <mingo@redhat.com>

Cc: Arnaldo Carvalho de Melo <acme@kernel.org>

Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>

Cc: Jiri Olsa <jolsa@redhat.com>

Cc: Namhyung Kim <namhyung@kernel.org>

Cc: Kan Liang <kan.liang@linux.intel.com>

Cc: Thomas Gleixner <tglx@linutronix.de>

Cc: Borislav Petkov <bp@alien8.de>

Cc: x86@kernel.org

Cc: "H. Peter Anvin" <hpa@zytor.com>

Cc: linux-perf-users@vger.kernel.org

Reviewed-by: Mark Rutland <mark.rutland@arm.com>

Reviewed-by: Thomas Gleixner <tglx@linutronix.de>

Signed-off-by: Rob Herring <robh@kernel.org>

Link: https://lore.kernel.org/r/20211208201124.310740-2-robh@kernel.org

Signed-off-by: Will Deacon <will@kernel.org>

Signed-off-by: Tony Jones <tonyj@suse.de>

---

 arch/x86/events/core.c       | 10 +++++-----

 arch/x86/events/perf_event.h |  2 +-

 include/linux/perf_event.h   |  9 +++++++++

 3 files changed, 15 insertions(+), 6 deletions(-)

diff --git a/arch/x86/events/core.c b/arch/x86/events/core.c

index 38b2c779146f..68dea7ce6a22 100644

--- a/arch/x86/events/core.c

+++ b/arch/x86/events/core.c

@@ -2476,7 +2476,7 @@ static int x86_pmu_event_init(struct perf_event *event)

 	if (READ_ONCE(x86_pmu.attr_rdpmc) &&

 	    !(event->hw.flags & PERF_X86_EVENT_LARGE_PEBS))

-		event->hw.flags |= PERF_X86_EVENT_RDPMC_ALLOWED;

+		event->hw.flags |= PERF_EVENT_FLAG_USER_READ_CNT;

 	return err;

 }

@@ -2510,7 +2510,7 @@ void perf_clear_dirty_counters(void)

 static void x86_pmu_event_mapped(struct perf_event *event, struct mm_struct *mm)

 {

-	if (!(event->hw.flags & PERF_X86_EVENT_RDPMC_ALLOWED))

+	if (!(event->hw.flags & PERF_EVENT_FLAG_USER_READ_CNT))

 		return;

 	/*

@@ -2531,7 +2531,7 @@ static void x86_pmu_event_mapped(struct perf_event *event, struct mm_struct *mm)

 static void x86_pmu_event_unmapped(struct perf_event *event, struct mm_struct *mm)

 {

-	if (!(event->hw.flags & PERF_X86_EVENT_RDPMC_ALLOWED))

+	if (!(event->hw.flags & PERF_EVENT_FLAG_USER_READ_CNT))

 		return;

 	if (atomic_dec_and_test(&mm->context.perf_rdpmc_allowed))

@@ -2542,7 +2542,7 @@ static int x86_pmu_event_idx(struct perf_event *event)

 {

 	struct hw_perf_event *hwc = &event->hw;

-	if (!(hwc->flags & PERF_X86_EVENT_RDPMC_ALLOWED))

+	if (!(hwc->flags & PERF_EVENT_FLAG_USER_READ_CNT))

 		return 0;

 	if (is_metric_idx(hwc->idx))

@@ -2725,7 +2725,7 @@ void arch_perf_update_userpage(struct perf_event *event,

 	userpg->cap_user_time = 0;

 	userpg->cap_user_time_zero = 0;

 	userpg->cap_user_rdpmc =

-		!!(event->hw.flags & PERF_X86_EVENT_RDPMC_ALLOWED);

+		!!(event->hw.flags & PERF_EVENT_FLAG_USER_READ_CNT);

 	userpg->pmc_width = x86_pmu.cntval_bits;

 	if (!using_native_sched_clock() || !sched_clock_stable())

diff --git a/arch/x86/events/perf_event.h b/arch/x86/events/perf_event.h

index 5480db242083..9d376e528dfc 100644

--- a/arch/x86/events/perf_event.h

+++ b/arch/x86/events/perf_event.h

@@ -74,7 +74,7 @@ static inline bool constraint_match(struct event_constraint *c, u64 ecode)

 #define PERF_X86_EVENT_PEBS_NA_HSW	0x0010 /* haswell style datala, unknown */

 #define PERF_X86_EVENT_EXCL		0x0020 /* HT exclusivity on counter */

 #define PERF_X86_EVENT_DYNAMIC		0x0040 /* dynamic alloc'd constraint */

-#define PERF_X86_EVENT_RDPMC_ALLOWED	0x0080 /* grant rdpmc permission */

+

 #define PERF_X86_EVENT_EXCL_ACCT	0x0100 /* accounted EXCL event */

 #define PERF_X86_EVENT_AUTO_RELOAD	0x0200 /* use PEBS auto-reload */

 #define PERF_X86_EVENT_LARGE_PEBS	0x0400 /* use large PEBS */

diff --git a/include/linux/perf_event.h b/include/linux/perf_event.h

index 0dcfd265beed..ba9467972c09 100644

--- a/include/linux/perf_event.h

+++ b/include/linux/perf_event.h

@@ -129,6 +129,15 @@ struct hw_perf_event_extra {

 	int		idx;	/* index in shared_regs->regs[] */

 };

+/**

+ * hw_perf_event::flag values

+ *

+ * PERF_EVENT_FLAG_ARCH bits are reserved for architecture-specific

+ * usage.

+ */

+#define PERF_EVENT_FLAG_ARCH			0x0000ffff

+#define PERF_EVENT_FLAG_USER_READ_CNT		0x80000000

+

 /**

  * struct hw_perf_event - performance event hardware details:

  */